//power.c -- 计算数的整数幂
#include<stdio.h>
double power(double n, int p);//ANSI 函数原型

int main(void)
{
    double x, xpow;
    int exp;

    printf("Enter a number and the positive integer power");
    printf("to which\nthe number will be raised. Enter q");
    printf(" to quit.\n");
    while(scanf("%lf%d", &x, &exp) == 2)
    {
        xpow = power(x, exp);//函数调用
        printf("%.3g to the power %d is %.5g\n", x, exp, xpow);
        //g格式：自动选f格式或e格式中较短的一种输出，且不输出无意义的零。
        printf("Enter next pair of numbers or q to quit.\n");
    }
    printf("Hope you enjoyed this power trip -- bye!\n");

    return 0;
}

double power(double n, int p)   //函数定义
{
    double pow = 1;
    int i;

    for(i = 1; i <= p; i++)
    {
        pow *= n;
    }
    
    return pow; //返回pow的值
}